Germinating Seeds Indoors

To start your seeds indoors, all you need is a container and tray, potting mix, and labels.

Are you eager to get a head start on your vegetable garden? We are here to tell you it’s possible to do so! While many will wait until the vegetable plants have become available at local retailers, starting your own seed indoors will yield faster produce and allow you to raise the varieties you want without relying on what the retailers have available. To start your seeds indoors, all you need is a container and tray, potting mix, and labels. The container you choose should have drainage holes and could be anything including egg cartons, cell packs saved from last spring, or special seed starting kits you purchase. The tray or flat will collect excess water coming through the drainage hole. Seeds will germinate best in light soil mixtures, specifically those developed for seed starting (readily available at most stores). Fill your container with the chosen mixture and water slowly and thoroughly. Now, your seed is ready to be planted and labeled! Check the seed packet to see whether you should cover the seeds or not. Some seeds need light to germinate and should not be covered, while others should be covered with a light dusting of soil mix. Use a mister bottle of water to water the seed after it has been placed appropriately. Your germinating mix should stay moist, but you do not want to overwater. Enclosing the whole container in plastic will help create a more humid, greenhouse-like environment. *Tip: A clear plastic deli container makes a great mini-greenhouse. Once the seeds start to sprout, remove the cover.

It is important to time your seed starting process so they will be ready to transplant outside after the last frost date in your area. Seed packets will often times contain this information, but here is a timetable to help you determine when to start:

The average date of the last spring frost in central Illinois is April 15. This means there is a 50 percent or less chance of frost on this date. The actual frost-free date for central Illinois is May 12. So to plant tomatoes on May 15, you’ll need to start tomato seeds indoors between March 20 and April 3rd.

  • 6-8 weeks: Pepper, tomato, eggplant, cauliflower, kohlrabi
  • 4-6 weeks: Swiss chard, cabbage, Brussels sprouts, broccoli, lettuce
  • 3-4 weeks: Watermelon, squash, muskmelon, cucumber, gourd
Ready? Set? Plant! All information sourced from University of Illinois Extension.